Improved washing operation for cathode ray tube manufacturing process



Oct. 6, 1959 P. n. PAYNE, JR 2,907,688

IMPROVED WASHING OPERATION FOR CATHODE RAY TUBE MANUFACTURING PROCESS Filed Sept. 1, 1955 Pl .1. Z

Z 20 f f z 19 INVENTOR. Pfiz/L 0. Pay/7a, JR. BY

United States Patent IMPROVED WASHING OPERATION FOR CATH- ODE RAY TUBE MANUFACTURING PROCESS Paul D. Payne, Jr., Chalfont, Pa., assignor to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania t Application September '1, 1955, Serial No. 531,873

11 Claims. (Cl. 134 -23) The present invention relates to a process for removing loose particles from a surface and to apparatus for carrying out this process, the instant disclosure being a continuation-in-part of my earlier application, Serial No. 466,564, filed November 3, 1954, now abandoned, and entitled ManufacturingProcess and Apparatus Therefor. Moreparticularly, the invention relates to a process, practiced in conjunction with other processes in the formation of a cathode ray tube screen structure, for removing, from the interior surface of the cathode ray tube faceplate, those screen constituent materials which are loosely attached to the faceplate, while leaving in place those materials which are firmly attached. The invention also relates to, apparatus for carrying out the foregoing process.

While the process and apparatus under consideration is useful in the manufacture of all types of cathode ray tube screen structures it is particularly useful in the manufacture of screens adapted for the reproduction of color television images. In certain forms such screen structures comprise a large,number of minute, discrete phosphor elements, all of which are deposited side-byside upon the glass faceplate of the cathode ray tube and different ones of which are responsive to impingement by an electron beam to emit light in different colors. These phosphor elements are formed by a photographic process which involves the deposition, over the entire faceplate, of a substantially uniform layer of phosphor material emissive of light in one of the aforementioned colorsv The entire faceplate is also coated with a layer of photosensitive material and those regions of this layer in which it is desired to form phosphor elements emissive of light inthe said color are exposed to illumination through a suitable optical mask. The entire faceplate is then covered with a layer of a phosphor material emissive of light in a second color and a second layer of photosensitive material is selectively exposed only in those regions in which it is desired to form elements of this second phosphor material. The foregoing steps are repeated until all of the different phosphors have been deposited and until their associated photosensitive layers have been selectively exposed. To avoid mixing between successively deposited phosphors, it is customary to follow each exposure of photosensitive material with a washing operation, using a solvent which is effective to remove, selectively, only the unexposed portions of this photosensitive material and, with it, those portions of the phosphor material which occupy the same regions of the faceplate as the unexposed photosensitive material. As a result of this washing operation only those phosphor elements which are held in place firmly by exposed, insoluble portions of the photosensitive material will still be present on the faceplate when the next layer of phosphor material is deposited. i

It is believed to be apparent that the aforedescribed washing operation is one of the steps of the manufacturing process which requires especiallyclose control, as

it must be effective to remove all of the undesired phos- 2,907,688 Patented Oct. 6, 1959 phor materials without removing any of the desired phosphor materials. I

Various unsuccessful attempts have been made to devise a washing process which provides the required degree of control For example, the faceplate, together with the phosphor layer and the selectively exposed photosensitive material, has been immersed in water, following which the water was agitated. This resulted in some of the phosphor from unexposed regions being carried over to, and deposited on exposed regions of the photosensitive material. There the phosphor adhered and consequently modified the light emission characteristics of these latter regions. It has also been attempted to effect the required washing operation by spraying the previously, formed portions of the screen.

structure with the solvent. However the impact of this spray not only removed the undesired materials, but also produced irregular removal of phosphor from those portions of the screen on which it was desired to leave the phosphor in place. t

Accordingly it is a primary object of the invention to provide apparatus for removing selectively from a substrate materials which are loosely attached to this substrate while leaving in place materials which" are firmly attached.

It is another object of the invention. to provide apparatus for washing off, from the faceplate of a cathode ray tube, unexposed photosensitive material and cathode ray tube screen constituent material occupying the same region on said substrate as, the unexposed photosensitive material, while leaving in place exposed photosensitive material ands creen constituent material held in place by this exposed. material.

. It is still another object of the inventionto effect the aforementioned selective removal of screen constituent material without contaminating other regions of the 'faceplate with theremoved material and without deforming materials deposited in these other regions.

To achieve these and still other objects which will appeanthe faceplate to be treatedshould be attached, prior to treatment, to a funnel-shaped member whose axis of symmetry is generally transverse to the plane of the faceplate and whose interior surface is shaped so as to provide a smooth, fillet-like transition between the edge of its wider opening. and the'adjacent edge of'the interior surface of the faceplate. In a cathode ray tube the funnel-shaped portion of the envelopewhich normally connects the faceplate to the neck may serve as this funnel-shaped member. The assembly composed of faceplate and funnel is then mounted in such aposition that every portion of the inner surface of the faceplate faces in a direction which has an appreciable downward component. As a result of this positioning, particles removed from this inner surface will tend to fall away from the surface under theinfiuence of gravity. While in this position the assembly is rotated about the axis of the funnel at a predetermined rate and a stream of washing liquid is projected against the inner surface of the funnel with such velocity and direction as to cause this stream to flow outward. and upward along the funnel fromits area of impingement toward and across the faceplate and down again along the interior surface of the funnel on the side opposite the area of impingement. In accordance with the, invention the projection of.this washingliquid is initiated at a time which is coordinated with the rotation of the assembly in such manner that, at any point onthe faceplate, the washing liquid is maintained in continuous motion from the time when liquid first begins flowing across this point until the time when the washing operation is complete. i

The manner of practicing my newprocess and the form of apparatus suitable for use therein will be more readily understood by reference to the accompanying drawings wherein Figure 1 represents a partly diagrammatic elevation of a machine for carrying out the screen washing process in accordance with my invention and Figure 2 is. a plan view of certain components of the apparatus illustrated in Figure 1 and serves to illustrate eertan spatial relationships between these components.

Referring to Figure 1 in more detail, the apparatus illustrated therein comprises a rigid frame member which serves to support the remainder of the apparatus. The top surface of this frame member is provided with a generally circular aperture throughwhich extends downwardly 'the funnel-shaped portion 11a of the faceplateanthfunnel assembly 11; This assembly is supported within anapprdpriately-shaped aperture in a turntable 12 which; in turn, is rotatably supported on frame member 10 in a manner explained in detail hereinafter. The shape of the aperture in turntable 12 will naturally depend upon th CIO S SECfiOIl of funnel 11a and the latter will, in turn, depend upon the shape of the faceplate. In particular, ifthe faceplate isrectangular, then the crosssection of the funnel and the aperture in turntable 12 will normally also be rectangular, Figure 2 illustrates in plan view and for the case of a rectangular faceplate, the relative positions of the faceplate 11b, of the turntable 12 and (in broken lines) that of the rectangular aperture in the turntable. Since the faceplate and funnel are often made of glass and are therefore fragile they are preferably not permitted to come into direct contact with the turntable 12 but are supported within the aperture in the latter by resilient buffers 13 distributed along the periphery; of this aperture. In the lower surface of turntable 12there is provided, near its outer edge, a circular groove 14 which forms a track in which run a num ber of wheels 15, each mounted for rotation about a horizontal axis near the inner edge of the circular aperture in the top of frame member 10'. An electric motor 16,;is mounted on frame member 10 and is mechanically con nected to at least one of the wheels 15, in any conventional manner, so as to cause rotation of this wheel when the motor is energized. The other wheels may be free running. When this motor 16 is energized and the wheel v to which it is connected is caused to rotate it will obviously cause rotation of turntable 12 and, with it, of bulb assembly 11. The turntable 12 and the driving mechanism therefor are preferably so arranged that this rotation of bulb assembly 11 takes place substantially about the axis of symmetry of the assembly.

A tube or pipe 17 extends into the interior of bulb assemblyll through the lower, open end of funnel 11a. This pipe is connected, at the end external of the bulb assembly 11, to a solenoid-operated valve 18 which, in turn, receives a supply of washing liquid through a connecting pipe 19 from a suitable source of such liquid (not shown). The end of pipe 17 which extends into the interior of assembly 11 is provided with a nozzle 17a which is placed at such a distance from the faceplate 11b and oriented at such an angle with respect to the axis of the bulb assembly that liquid emerging therefrom will strike the interior surface of funnel 11a in an area in which this surface is divergent fromthe-aforementioned axis and in a direction which has a component parallel to this axis. The precise location and orientation of this nozzle 1 7a depends on anumber of factors which will be discussed in more detail hereinafter. In any case, however, the orientation of this nozzle, in a vertical plane will have tolbe such t a the tr m o qu ssu n ere m as a. ir ction h ch de ate pward y om t e n m l to e int rior surface of the funn .1. A cup-shap receptacle 20, wider than the open end of funnel 11a, is disposed-directly beneath the open end of this funnel and is connected to an outlet pipe. 21 which carries liquid collected by receptacle away from the. washing apl?I-l1$.-, i

A tab member 22 is attached to the turntable 12 so as to form a cam-like surface projecting beyond the edge of this turntable. On frame 10 near this turntable there is mounted a switch 23 provided with an actuating lever 24 which is placed near the outer rim of the turntable in such manner as to be displaced from its normal position by the passage of tab 22. This displacement of the lever actuates the switch 23- and this in turn causes the solenoid valve 18 to open and also initiates the operation of a timing mechanism 25 which closes valve 18 again after an interval of predetermined duration, v

The operation of the foregoing apparatus is as follows. The bulb assembly 11 is placed in the aperture in turntable'12 and the motor 16 is energized, thereby causing turntable 12 and bulb assembly 11 to rotate. For illustrative purposes let it be assumed that this rotation is in a clockwise direction, as indicated by the curved arrow in Fig. 2. When, during the rotation of turntable 12, the tab 22 strikes lever 24 and actuates switch 23, valve 18 is opened and a stream of washing liquid is directed from nozzle 17a toward bulb assembly 11. At a predetermined time later, under the control of the aforementioned time ing device, the valve 18 is closed again and the supply of washing liquid to the bulb assembly is thereby interrupted. The motor may then be deenergized and the assembly 11 may be removed from its position in turn-v table 12 for further processing.

It will be recalled that I have found that the shortcomings of the prior art washing methods can be over-. come by making sure that, during the Washing operation carried out-according to my invention, the flow of wash: ing liquid across any given point on the faceplate is never interrupted. It is believed to be apparent that, in

view of the wide variations in design and operating conditions to which several of the aforedescribed components are subject, considerable care must be taken in selecting these components and their operating conditions if the desired mode ,of operation is to be obtained. The con: siderations which govern this selection will now be discussed.

I have found that, particularly in the treatment of faceplates which are not symmetrical about their axes of rotation, one of the most critical factors in the successful operation of the apparatus embodying the invention is the location of the area in which the stream of washing liquid initially impinges upon the inner surface of funnel'll a. More particularly I have found that if this area of initial impingement is properly located, then other parameters may be varied within unexpectedly wide limits and still the. desired pattern of liquid flow across the faceplate will be produced. If, on the other hand, this, area of initial impingement is improperly located, then it maybe extremely difficult to find a combination of the other pa- 1 rameters which will produce an acceptable fiow pattern.

This broken line represents the path followed by the washing liquid between nozzle 17a'and the area of impingement.

It will be apparent that,.with the apparatus illustrated in Figs. 1 and Z, the desired azimuthal location of this area of initial impingement, measured in the plane, of rotation of the bulb assembly, is established by appropriate coordination between the rate of rotation of the assembly, the position of tab 22 and switch lever 24, the

azimuthal orientation ofnozzle 17: and the velocity. with which the liquid issues from the nozzle- While it is considered to be well within the skill of a worker in the Distancejbetween nozzle 17a and center of face- 1 plate -Q. "inches" Inclination of nozzle 17a with respect to the verftical degrees 65 Diameter of nozzle 17a inch /2 Distance between stream impact area and edge of faceplate, measured along the interior surface of funnel 11a inch 5.5 Rate of rotation of bulb assembly 11 r.p.m 12 Rate of flow of washing liquid gallons/minute 8 Liquid pressure lbs./sq. inch; 11

It will be noted that the foregoing list of parameters includes neither the position of cam22 and switch lever 24, nor the azimuthal orientation of nozzle 17a. This is because the relationship between these latter parameters dependsupon factors, such as the time delay between the closing of switch 23, and the opening of valve 18, which vary widely from one kind of valve to another. This' relationship also depends upon the time which elapsesbetween the opening of the valve and the issue of liquid from nozzle 17a, and this time in turn depends upon the length of pipe 17. However, once these parameters have been established in any particular installation, it becomes an extremely simple matter to determine the aforementioned positional parameters. This may be done, for example,by selecting any arbitrary lo cation for cam 22 on the periphery of turntable 12 and any arbitrary orientation for nozzle 17w, then rotating a test, assembly in the turntable and manually adjusting the azimuthal location of switch lever 24, along the turntable periphery,, until visual inspection indicates that the area of initial liquid impingement is actually in its proper location. Alternatively, elementary geometrical considerations, also well within the skill of a worker in the art will lead to the proper relative positions of the components under consideration. While, in the specific embodiment illustrated, the assembly 11 is positioned with the funnel axis vertical it will be understood that this axis may also be inclined with respect to the vertical provided, however, that the inclination is not sufficiently great to place the faceplate in a position in which gravity will tend to pull particles removed from its interior surface back to this surface. As a matter of fact it is sometimes advantageous to position the assembly 11 with thefunnel axis inclined with respect'to the vertical (subject to the aforementioned limitation) as this will bring the faceplate into a position in which gravity will aid the flow, across it, of water applied near its top edge,with the result that this water can be projected fromnozzle 17a with reduced pressure. This is desirable not only because it permits the use of a less powerful pump but also because itreduces the erosive eifect of the water upon that material present on the faceplate which it is desired not to remove. Itis believed to .be well within the skill of the art to reproportion the various parameters involved in the washing operation to yield successful operation in accordance with the aforestated principles for any useful degree of inclination of the assembly.

For the treatment of rectangular faceplates, the precise shape of the aperture in nozzle 17a, from which the stream of .washing liquid issues, is not critical, and may, for example, be either circular or square. However there are other faceplate'configurations for which this aperture shape'is .of considerable importance. For example, for the treatment of circular faceplates it is preferable to provide a nozzle having an aperture of trapezoidal shape. ,This aperture is preferably so oriented that its parallel edges lie in vertical planesand that its mutually inclined edges lie in planes which converge in the direction of motion of the portion of the envelope which confronts the aperture. For other faceplate configurations still other nozzle aperture shapes will be best,

'but for anyparticular case, a suitable form can be readily determined by one skilledin the art.

The duration of the washing operation is also; sub.- jeot to variations to accommodate variations in the thickness of the material to be removed and also inthe degree of adherence of this material to its substrate. This duration can readily be adjusted to any desired value, by varying the adjustment of the timing mechanism 25 in Fig. l. r

The invention has been described in detail in its application to the removal of loosely deposited phosphors from the faceplate of a'cathode ray tube. It will be understood, however, that it is equally useful for the selective removal of portions of other screen constituent materials such as, for example, materials having high secondary electron emissivities, which are sometimes incorporated in certain regions of the screen structures of color cathode ray tubes in order to provide distinctive electrical indications ofbeam impingement upon these regions. Finally it is desired to point out that the process and apparatus described is suitable forthe treatment of structures which are not intended for use in cathode ray tubes at-all but which present, for any reason, a similar problem of selective removal of materials loosely deposited on a substrate.

It will be understood that the particular apparatus illustrated is also subject to numerous modifications without departing from the scope of myinvention. For example, this apparatus has been shown equippedwith the controls which are. necessary to make, its operation essentially automatic. It will be understood, however, that, where speed of processing is not essentiahcertain of thecontrol operations may be carried out by hand. In particular the opening of valve 18, which initiates the delivery of washing liquid to the bulb assembly, may be carried out manually by an operator. Since the assembly rotates slowly, it is entirely feasible for an operator to determine the proper instant, during revolution, for opening this valve. Similarly it is feasibleto stop the delivery of washing fluid manually upon observing that the fluid issuing from the discharge pipe 21 no longer contains appreciable quantities of the material which is being removed.

Manual operation is also indicated when bulbs of different shapes and sizes are to be processed in succession. This is because the expense of providing and presetting the equipment necessary for automatic operation can be justified only if an appreciable quantity of bulbs of the same configuration are to be processed successively.

In the particular case illustrated, the bulb assembly comprises, during washing, only the faceplate and the funnel. However, it may be desirablein some instances to carry out a washing operation, in accordance with the invention, after the neck of the tube has also been attached to the assembly. In that event, it is preferable to introduce, into the interior of the bulb assembly, not only the pipe 17 but also an air pipe (not shown) hav ing an orifice near nozzle 17a and supplied with compressed air at a pressure slightly in excess of atmospheric pressure. This compressed air will serve to evacuate promptly the used washing fluid from the interior of the assembly despite the constriction provided by the neck portion. i

Also, in the particular case illustrated the-bulb assembly is rotated while the nozzle is held stationary. This mode of operation is preferred because its use eliminates the need for a rotating joint in pipe 17. However, it is entirely practical, if desired, to rotate this pipe 17 and the attached nozzle 17a, while maintaining the bulb assembly stationary, or even to rotate both the bulb and the pipe. All that is required, in accordance with my invention is that there be produced the necessary relative rotation between these two structures;

In view of these and still other modifications which will occur to those skilled in the art, it is desired that the scope of the invention be limited only by the appended claims. i

' 'Iclaim:

*1, The process of treating an envelope having a funnelshaped portion and an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: supporting said envelope with said end portion uppermost and with its axis in such a position that every portion of the interior surface of said end portion faces in a direction which has a downward component, projecting upon the interior surface of saidfunnel-shaped portion in the vicinity of said closed end portion a stream of liquid with such velocity and direction as to cause said stream to flow up toward and across said interior surface of said end portion while preventing impingement of any portion of said stream directly upon said end portion, and producing relative rotation about said axis between said stream and said envelope.

' 2. The process of treating an envelope having a funnelshaped portion and having an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: supportingsaid envelope with said end portion uppermost and with its axis in such a position that every portion of the interior surface of said end portion faces in a direction which has a downward component, projecting upon the interior surface of said funnel-shaped portion in the vicinity of said closed end portion a streamof liquid with such velocity and direction as to cause said liquid to flow up toward and across said interior surface of said end portion while preventing impingement of any portion of said stream directly upon said end portion, and rotating said envelope about said axis.

3. The process oftreating an envelope having a funnelshaped portion and having an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: supporting said envelope with said end portion uppermost and with its axis in such a position that every portion of the interior surface of said end portion faces in a direction which has a downward component, projecting toward the interior surface of said funnel-shaped portion in the vicinity of said closed end portion astream of liquid in a direction which deviates upwardly from the normal to said funnel surfaceand with sufiicient velocity to cause said liquid to flow along said funnel surface up toward and across said interior surface of said end portion while preventing impingement of any portion of said stream directly-upon said end portion, and producing'relative rotation about said axis'between said stream and said envelope. i

4. The process of treating anenvelope having a funnelshaped portion of substantiallyrectangular cross-section and having an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: rotating said envelope about its axis while supporting said envelope with said end portion uppermost and withsaid axis in such a position that every portion of the interior surface of said end por: tion faces'in a direction which has a downward component, and projecting upon the interior surface of said funnel-shaped portion a stream of liquid with such velocity and with such direction, measured in a vertical plane, as to causesaid liquid to flow up toward and across said interior surface of said end portion and with such di e t on. me ure in a; r zonta p as t cau e sa s ream to mpin e nit l y upo area of said funnel-shaped portion which lies just behind the edge of one of its wider surfaces which occupies the leading position as said envelope is rotated.

5. Apparatus for treating an envelope having a funnelshaped portion and having an end portion which closes the wider opening of said funnel-shaped portion, said apparatus comprising: means for supporting said enve lope with said end portion uppermost and its axis in such a position that every portion of the interior surface of said end portion faces in a direction which has a downward component; means for rotating said assembly about said axis; and means for projectin stream of liquid upon the interior surface of said funnelshaped portion inthe vicinity of said closed end portion with such velocity and direction as to cause said liquid to flow up toward and across said interior surface said end portion, said projecting means being constructed to preclude impingement of any portion of said stream directly upon said end portion. 1

6. Apparatus for treating an envelope having a funnelshaped portion and having an end portion which closes the wider opening of said funnel-shaped portion, said apparatus comprising: means for supporting said enve lope with said end portion uppermost and with'its axis in such a position'that every portion of the interior surface of said end portion faces in a direction which has a downward component; means-for rotating said envelope about said axis in a predetermined direction and at apredetermined angular velocityfmeans actua-t able to project a stream of liquid upon the interior surface of said funnel-shaped portion with such velocity and direction as to cause said liquid to flow up toward and across said interior surface of said endportioi said projecting means being constructed to preclude 'irn pingement of any portion of said stream directly upon said end portion; and means for actuating said projecting means while said envelopeis rotating, a V V 7. Apparatus for treating an envelope having a funnel shaped portion of substantially rectangular cross-section and having an end portion which closesthe wider open ing of said funnel-shaped portion,said apparatus comprising: means for supporting said envelope with said end portion uppermost and with its axis in such a position that every portion of the interior surface oflt flid end portion faces in a direction which has a downward component; means for rotating said envelope about said axis in a predetermined direction and at a predetermined angular velocity; means actuatable to project, a stream of liquid upon the interior surface of said funnel: shaped portion with such velocity and direction, as to cause said liquid to flow up toward and across said interior surface of said end portion; and means for actuiating said projectingmeans at such a time during any given revolution of said envelope about said axis that said stream initially impinges upon an area of funnelshaped portion which is located just behind the edge of one of the wider surfaces of said'funnel-shaped portion which occupies the leading position as said envelope is rotated. T

8. Apparatus for treating a cathode ray tube enye lope including the funnel-shaped portion and the face; plate thereof, said apparatus comprising: means for supporting said envelope with its axis in a substantially vertical position and with said faceplate uppermost} means for rotating said envelope about said axis; means for projecting a stream of liquid upon the interiorlsurface of said funnel-shaped portion in the vicinity of said faceplate with such velocity anddirection as to cause said liquid to flow up toward and across the interior surface of said faceplate, said projecting means being constructed so as to preclude the impingement orany portion of said stream directly upon said faceplate.

9. The process of treating an envelope having a funnelshaped portion and an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: supporting said envelope with its axis in a substantially vertical position and with said end portion uppermost, projecting upon the interior surface of said funnel-shaped portion in the vicinity of said closed end portion a stream of liquid with such velocity and direction as to cause said stream to flow up toward and across the interior surface of said end portion while preventing impingement of any portion of said stream directly upon said end portion, and producing relative rotation about said axis between said stream and said envelope.

10. The process of treating an envelope having a funnel-shaped portion of substantially rectangular crosssection and having an end portion which closes the wider opening of said funnel-shaped portion, said process comprising the steps of: rotating said envelope about its axis while supporting said envelope with said axis in a substantially vertical position and with said end portion uppermost, and projecting upon the interior surface of said funnel-shaped portion a stream of liquid with such velocity and with such direction, measured in a vertical plane, as to cause said liquid to flow up toward and across the interior surface of said end portion and with such direction, measured in a horizontal plane, as to cause said stream to impinge initially upon an area of said funnel-shaped portion which lies just behind the edge of one of its wider surfaces which occupies the leading position as said envelope is rotated.

11. Apparatus for treating an envelope having a 10 funnel-shaped portion of substantially rectangular crosssection and having an end portion which. closes the wider opening of said funnel-shaped portion, said apparatus comprising: means for supporting said envelope with its axis in a substantially vertical position and with said end portion uppermost; means for rotating said envelope about said axis in a predetermined direction and at a predetermined angular velocity; means actuatable to project a stream of liquid upon the interior surface of said funnel-shaped portion with such velocity and direction as to cause said liquid to flow up toward and across the interior surface of said end portion; and means for actuating said projecting means at such a time during any given revolution of said envelope about said axis that said stream initially impinges upon an area of funnelshaped portion which is located just behind the edge of one of the wider surfaces of said funnel-shaped portion which occupies the leading position as said envelope is rotated.

References Cited in the file of this patent UNITED STATES PATENTS 1,825,718 Dufi'ord Oct. 6, 1931 2,062,664 Kendall Dec. 1, 1936 2,122,018 Wolif June 28, 1938 2,372,599 Natchman Mar. 27, 1945 2,538,445 Derbenwick Jan. 16, 1951 2,726,180 Stankey Dec. 6, 1955 2,730,068 Reynolds Jan. 10, 1956 2,763,564 McKenzie Sept. 18, 1956 

1. THE PROCESS OF TREATING AN ENVELOPE HAVING A FUNNELSHAPED PORTION AND AN END PORTION WHICH CLOSES THE WIDER OPENING OF SAID FUNNEL-SHAPED PORTION, SAID PROCESS COMPRISING THE STEPS OF: SUPPORTING SAID ENVELOPE WITH SAID END PORTION UPPERMOST AND WITH ITS AXIS IN SUCH A POSITION THAT EVERY PORTION OF THE INTERIOR SURFACE OF SAID END PORTION FACES IN A DIRECTION WHICH HAS A DOWNWARD COMPONENT, PROJECTING UPON THE INTERIOR SURFACE OF SAID FUNNEL-SHAPED PORTION IN THE VICINITY OF SAID CLOSED END PORTION A STREAM OF LIQUID WITH SUCH VELOCITY AND DIRECTION AS TO CAUSE SAID STREAM TO FLOW UP TOWARD AND ACROSS SAID INTERIOR SURFACE OF SAID END PORTION WHILE PREVENTING IMPINGEMENT OF ANY PORTION OF SAID STREAM DIRECTLY UPON SAID END PORTION, AND PRODUCING RELATIVE ROTATION ABOUT SAID AXIS BETWEEN SAID STREAM AND SAID ENVELOPE.
 5. APPARATUS FOR TREATING AN ENVELOPE HAVING A FUNNELSHAPED PORTION AND HAVING AN END PORTION WHICH CLOSES THE WIDER OPENING OF SAID FUNNEL-SHAPED PORTION, SAID APPARATUS COMPRISING: MEANS FOR SUPPORTING SAID ENVELOPE WITH SAID END PORTION UPPERMOST AND WITH ITS AXIS IN SUCH A POSITION THAT EVERY PORTION OF THE INTERIOR SURFACE OF SAID END PORTION FACES IN A DIRECTION WHICH HAS A DOWNWARD COMPONENT; MEANS FOR PROJECTING A ASSEMBY ABOUT SAID AXIS; AND MEANS FOR PROJECTING A STREAM OF LIQUID UPON THE INTERIOR SURFACE OF SAID FUNNELSHAPED PORTION IN THE VICINITY OF SAID CLOSED END PORTION WITH SUCH VELOCITY AND DIRECTION AS TO CAUSE SAID LIQUID TO FLOW UP TOWARD AND ACROSS SAID INTERIOR SURFACE OF SAID END PORTION, SAID PROJECTING MEANS BEING CONSTRUCTED TO PRECLUDE IMPINGEMENT OF ANY PORTION OF SAID STREAM DIRECTLY UPON SAID END PORTION. 